In a landmark moment for cannabis law reform, the U.S. House of Representatives approved a measure late Thursday night to de-fund the federal war on medical marijuana. The provision passed the Senate Saturday and went to the White House Monday, where it is expected to be signed by President Obama, bringing a halt to the three-year-long medi-pot crackdown in California and other states.

The Hinchey-Rohrabacher Amendment to the $1.1 trillion cromnibus spending bill blocks the use of Department of Justice funds to “prevent [medical marijuana states] from implementing their own State laws that authorize the use, distribution, possession, or cultivation of medical marijuana.”

The vast majority of Americans (78 percent) support states’ right to allow access to medical cannabis.

The spending bill also contains a provision aimed at Washington DC legalization. The rider inserted by Republican Maryland Rep. Harris would prevent federal funds from being used to “enact or carry out any law, rule, or regulation to legalize or otherwise reduce penalties associated with the possession, use, or distribution of any schedule I substance under the Controlled Substances Act (21 U.S.C. 801 et seq.) or any tetrahydrocannabinols derivative.”

District activists say they will litigate the Harris rider.

Marijuana law reform advocates cheered the return of the Hinchey-Rohrabacher Amendment last week, calling it a “stunning victory.”

“For the first time, Congress is letting states set their own medical marijuana and hemp policies, a huge step forward for sensible drug policy,” stated Bill Piper, director of the Drug Policy Alliance’s office of national affairs. “States will continue to reform their marijuana laws and Congress will be forced to accommodate them. It’s not a question of if, but when, federal marijuana prohibition will be repealed.”

“This is a great day for patients and for public safety,” stated Major Neill Franklin (Ret.), executive director of Law Enforcement Against Prohibition, in a release. “Congress has finally listened to the vast majority of Americans who believe the federal government has no right to interfere in the personal decision to use medical marijuana made by a patient in consultation with his or her doctor. Law enforcement never should have been a part of that decision and if this amendment passes, they no longer will.”

The medical marijuana provision first passed the House in May, as a bipartisan amendment sponsored by Dana Rohrabacher (R, CA). Federal funds have been used to shut down scores of licensed, regulated dispensaries across the country, as well as prosecute and imprison providers. The federal government under the Obama Administration has spent about $300 million on enforcement in medical marijuana states, advocacy group Americans for Safe Access reports.

“This is great news for medical marijuana patients all across the country,” stated Rep. Sam Farr (D-CA), one of the co-authors of the House measure, in a press release. “This amendment protects patients while the federal government catches up with the views of the American people. Patients will have access to the care legal in their state without fear of federal prosecution. And our federal dollars will be spent more wisely on fighting actual crimes and not wasted going after patients.”

“We applaud this Congress for doing the right thing by protecting the rights of patients, and ending a years-long attack on the medical marijuana community,” stated Mike Liszewski, Government Affairs Director with Americans for Safe Access (ASA), the leading medical marijuana advocacy organization that has been championing the measure for years. “By approving this measure, Congress is siding with the vast majority of Americans who are calling for a change in how we enforce our federal marijuana laws.”

Marijuana Policy Project communications director Mason Tvert stated, “This legislation makes it clear that the D.E.A. has no business interfering in states’ medical marijuana laws. Taxpayer money should not be used to punish seriously ill people who use medical marijuana and the caregivers who provide it to them.”

Americans for Safe Access executive director Steph Sherer writes us that: “This is truly a long-fought victory for medical marijuana patients who have lived in fear of being caught in the crossfire of conflicting state and federal laws for nearly two decades. But this is also a victory for taxpayers because of the hundreds of millions of dollars saved on unnecessary and harmful enforcement.”

The DOJ measure would remain in effect until September 30, 2015, so advocates are working on stronger protections for patients, including HR 689, the “States’ Medical Marijuana Patient Protection Act”, which would reclassify marijuana for medical use, increase therapeutic research, and permanently end the 77 year-long war on medical cannabis.

“Now that we are in a ‘ceasefire,’ patients are ready to work with Congress on comprehensive medical marijuana legislation,” continued Sherer. “Passage of this measure has shown that Congress is ready to roll up its sleeves on this issue, and we’re ready to work together to bring about broader and more lasting change for the millions of Americans who rely on medical marijuana treatments.”

The amendment adds to the tailwinds for cannabis law reformers. On Monday, Texas legislator Rep. Joe Moody stated he will introduce a bill to reduce penalties for marijuana possession in Texas. Rep. Moody holds a press conference on the bill Monday morning alongside retired Texas District Court Judge John Delaney, Matt Simpson of the ACLU of Texas, and Ann Lee of Republicans Against Marijuana Prohibition.